Balance-staff for watches.



J. FREISTADTER.

- BALANCE STAFF FOR WATCHES.

APPLICATION FILED OCT. 7. m4.

1 1 3 59 5 Patented Apr. 20, 1915.

THE NORRIS PETERS 60.. PHOTU LI IHO. WASHINGTON. D. c

I To all whom it may concern Of the accompanying drawings forming a 1 part of this specification: Figure 1. 'repre-[ Be it known that I, "JACOB FnEIs'rADTER, a

citizen of the United States, andresident of Waltham, in the I I county of 'Middlesex and f State ofuMass'achusetts, :have invented oertain new and usefulqImprovements in Balance-Stafi's for Watches, ofwhich the following isa specification. I I This invention has for its object: topmvide a watch balance staff which iscapable .of being installedin a watch movement more conveniently and with greater facility than heretofore,v

claim.

sents a side view of abalance stafi' embodying myjinvention, shown on an enlarged scale, a portion of the balance, the hair spring icollet, the, roller table, the safety a roller, and the jewels and endstonesengaged I 3 with the staff being shown in section; I Fig,

2 represents an end view of the staff. y,

- The same reference charactersindicate the w 'samelor similar parts'in all the views.

i ders. The distance between the uppershoulder and the upper pivot 13 is the same as the distance between the lower shoulder a and the lower pivot13, The collar 14 611",

ters a recess 16 inthe hub engaged with that is, with either the upper jewel 18 bridge '19, and the otherrpivot engaged with" V the slower jewel20 in the lower'watch plate I 21. Either one of I table 23and a safety tions being preferablyslightly tapered"; as

- spring' colletor a safety roller and, aroller My improved balance staff is composed of I 7 two duplicate'end portions12, eachhaving'a I pivot 13, and each formed as an inverted facsimile of the other, and an intermediate collar'll theends of'which form stop "shoulthe arm' 17, of the balance. .Thestafi is adapted to beinstalledw'ith either end up, pivot 13; engaged; with 1n the balance cock or the 'duplicate end portions 12 is adapted collet 22 while the I p I roller 24,.said end pore shown, andiadaptedito'have a close fric- Specification of Letters I ate nt.

slightly in diame :reversible construction, I a T bearings do notfit each other satisfactorily v and it is embodied in a reversi-, ble balance stafl", having the I advantages, which I will now *proceedtodescribe and to engagea hair spring other engages aroller 'B A iE-S A ORIW CE'E i I therefor in the I find that when if the pivots I and pivots and the bearings jewels are liable to vary' ter, it being difiicul't if not; impossible'jto make each Pivotand bearing of exactly the same diameteras the other.

the stafiis of the described a I Patentedl ipr.20','1915[ Applicationfiledlilctober i',191$; iserialftl'o.865,42'3; I

l I 18iand Said when the staff isinstalledwith one end up,

the difficulty'can be overcome by the simple expedient of reversing the staff. The dupli- "cate form of' the staff portions 12 enables the collet 22 to beengaged with the upper po r., I

:tion, and the safety roller "23land the table roller 24; withthe lower-portion of the stafi, 1 it being immaterial which end of the staff a 7 0 is the upper end. The balance wheel-,is I i always located at the same relative height in the'xwatch whether one end ofthestafi' or the other isllppermost. "Byvaryin'gthei depth of the'recess 16 and the width of the i collar14, or both, the staff and collet canbe I; f I properly installed in any watch. The re' l versibility ofrthe staff practically doubles,

the -o'pportu'nity of fitting the sameztoan' J already completed watch, and is therefore especially useful in 'America'n and foreign machine-made watches.

the "collar 14, and

pivots 13, constitute facing "stops,

hub 15, .so' that the collar'determines the height] of the balance-wheel on the staff whether one endof the stafi' or the other is uppermost Said duplicate stops therefore the staff, and insure theflocationof the balanceatiits. propervheight without trials and The fixed shoulders formed by the ends of I i equidistant from the duplicate oppositely either of which is adapted to v abut against the usualshoulder formed by f I the inner end ofthe recess 161in the balance measuring, thus saving time and insuring accuracy in positioning the; balance.

Having described my invention, 1 claim "duplicate end portions, each havingapivot j A reversible balance stafi composed of and each formed to engage either a hair table, and an intermediate cylin'dricallbal I ance hub-engaging collar theends of which distance b'etweenfthe upper stop andthe upper pivot beingthesame as that'between I lowerstop and the lower pivot, each enil installed with either end portion uppermost,

and with either end portionengaged; With a hair spring collet and the other end portion engaged With a safety roller and a ftable' roller, the cylindrical form of said collar copies of this patent may beflohtained; for five cents each by adGreSsing the Commissioner of Patents, r if Viifashz'u.ng1:o1:., D. 0. v r i Permitting it m g a balancehub with f i eithen end of thestafii uppermost.

In testimony WhereofI" have afiixed my signature, in presence of tWo Witnesses.

-J AG'GDB FREISTADTER. i

Wit1iesses: f

ELLA P. BRANNEN, P. PEZZETTI. 

